Decoding instrument for a pin-type tumbler lock

ABSTRACT

A decoding instrument for a pin-type tumbler lock, the instrument including a frame having a decoder support for a plurality of shim-like, toothed decoders, the combined thickness of the support and decoders being less than the width of the keyreceiving slot in the barrel of a lock. These decoders are shiftable independently of one another and longitudinally of the support to detect the individual movement of the pins.

United States Patent 119] Nail] [111 3,827,151 [451 Aug. 6, 1974 DECODING INSTRUMENT FOR A PIN-TYPE 'TUMBLER LOCK Inventor: David W. Naill, 1498 Meadow Dr.,

El Cajon, Calif. 92021 Filed: May 12, 1971 Appl. No.: 142,483

U.S. Cl 33/174 F, 70/394 Int. Cl. G01b 5/20 Field of Search 33/174 F, 174 P, 174 PA,

References Cited UNITED STATES PATENTS /1955 Harwell ..33/l74F 12/1955 Tampke ..33/1741= Primary ExaminerLouis R. Prince Assistant ExaminerRichard R. Stearns Attorney, Agent, or FirmBrown & Martin; Neil F. Martin [5 7] ABSTRACT A decoding instrument for a pin-type tumbler lock, the instrument including a frame having a decoder support for a plurality of shim-like, toothed decoders, the combined thickness of the support and decoders being less than the width of the key-receiving slot in the barrel of a lock. These decoders are shiftable independently of one another and .longitudinally of the support to detect the individual movement of the pins.

5 Claims, 6 Drawing Figmres a7{ //2 so 9/ 1 2 Fa et I i 1 1. l I j PATENTEB 5W4 SHEET 2 BF 2 I wk wk DAVID W NA/LL INVENTOR.

ATTORNEY I DECODING INSTRUMENT FOR A PIN-TYPE TUMBLER LOCK BACKGROUND OF THE INVENTION 1. Field of the Invention:

The invention is directed to a decoder for a pin-type tumbler lock to be used by locksmiths.

2. Description of the Prior Art:

An independent search revealed only the following U.S. Pat. Nos. 2,791,840, May 14, 1957, to A. H. Harwell; 2,727,312, Dec. 20, 1955, to M. L. Tampke; 2,720,032, Oct. 11, 1955, to A. H. Harwell; 2,338,768, Jan. 11, 1944, to T. H. Johnstone; 2,087,423, July 20, 1937, to H. Abrams; 1,353,722, Sept. 21, 1920, to F. Clark; 2,059,376, Nov. 3, 1936, to J. Lombardo.

None of these patents discloses a decoder employing a plurality of shim-like decoders that are inserted simultaneously into the key-receiving'slot of a lock.

SUMMARY OF THE INVENTION A decoder for a pin-type tumbler lock that includes a frame having a support for a plurality of toothed, shim-like decoders. The combined thickness of the decoder support and the decoders is less than the width of the slot in the barrel of the lock that receives the actuating key for the lock. The decoders are adapted to be reciprocated independently of one another to detect independent movements of each of the pins. The frame includes indicia which, in combination with the movements of the decoders, can indicate the extent of movements of the pins thatis necessary to release the barrel for movement relative to the lock-body.

Other features and the advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the invention is illustrated.

' BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of the decoding instrument, said view being in full size;

FIG. 2 isa top plan view of the instrument shown on a larger scale;

FIG. 3 is a sectional view taken along approximately line 3-3 of FIG. 2;

FIGS. 4 and 5 are sectional views taken along lines 4-4 and 5-5, respectively, of FIG. 2, but on a larger scale; and

FIG. 6 is a cross sectional view of a lock and decoder, the section being taken along line 33 of FIG. 2, but on a larger scale.

DESCRIPTION OF THE PREFERRED EMBODIMENT The lock and the key (not shown) for actuating pins 22, 24, 26, 28 and 30 are of the type shown in the aforesaid Harwell U.S. Patent No. 2,791,840. The particular lock herein shown for illustrating the invention is that employed in the Ford automobiles for controlling the ignition and the motor for starting the engine.

actuating key (not shown). A plurality of aligned bores 38 extend radially outwardly from the slot 36. These bores are alignable with bores 40 in the body 32 of the lock. Another set of pins 42, 44, 46, 48 and 50 is disposed in the bores 40 and the inner ends thereof are adapted to engage the outer ends, respectively, of pins 22, 24, 26, 28 and 30. A set of springs 42 yieldingly urges all pins inwardly. The combined length of the alignable pins of each pair of pins is the same, but the pins of a pair of pins are of unequal length relative to one another. Therefore, to turn the barrel, the key must be of such contour of aligned teeth so as to move the pins 22, 24, 26, 28 and 30 to positions in which the outer ends thereof extend to the periphery of the barrel.

Referring now to the decoder instrument 52, it includes a frame 54 having a front wall 56 and a rear wall 58, which walls are spaced from one another by spacers 60 and 62. The spacers are held in place by end screws 64 and an intermediate screw 65. The frame includes a decoder support 66 which may be formed integrally with spacer 62. The support 66 is elongated and is provided with an elongated shoulder 68.

A plurality of shim-like decoders, five being herein shown and referred to as decoders 70, 72, 74, 76 and 78, are adapted to be reciprocated and are guided by a slot 80 in the spacer 62 and by the shoulder 68. Five levers 82, 84, 86, 88 and 90 are pivotally mounted on a post 112 which is fixed to and spans the frame walls 56 and 58. As viewed in the drawing, the left ends of the decoders are connected with the levers, the decoders 70, 72, 74, 76 and 78 being pivotally attached, respectively, to levers 82, 84, 86, 88 and 90 by pin 91. The levers are movable independently of one another for independent reciprocation of the decoders.

lndicia in the form of numerals l, 2, 3, 4 and 5 are placed on an extension 92 on the frame front wall 56 and each of the levers can be aligned with the numerals on the wall 56 by moving the lever.

The combined thickness of the decoder support 66 and the five decoders is less than the width of the slot 36 in the barrel 34.

The decoding is effected by shifting the decoders separately. Each decoder 70, 72, 74, 76 and 78 is provided, respectively, with a single tooth 94, 96, 98, and 102 that extends toward pins 22, 24, 26, 28 and 30, respectively. In determining the shape of the key for actuating the lock, the decoder support 66 and the five decoders are inserted in the barrel 34 through the slot 7 50 upwardly. This movement is continued until resistance to further movement is encountered due to the fact that the pin 50 is being pushed by the tooth 102 into engagement with the inner margin 104 of lockbody 32. This is known as the condition of resistance to movement of the pin. This resistance can be felt by the operator and the operator is then aware that the pin is moved to the margin 104. The lever 90 is maintained in that position and thereafter each of the other levers is shifted to the left individually until they each encounter resistance. At least one and usually moreof the positions of levers 82, 84, 86 and 88 will be shifted more or less than lever 90 has been shifted. The instrument can now be turned. The decoder can then be withdrawn and a record is made of the positions of the levers with respect to the indicia (numerals) on extension 92. Having the data, as indicated by the positions of the levers with respect to the indicia, the exact depths can be cut in a key blank.

It is readily realized that by virtue of the present invention, I have provided a decoding instrument which materially reduces the time necessarily expended by locksmiths in determining how a key blank should be cut. Also, all parts of the decoding instrument are formed as a unit. The locksmith requires this unit only to decode a tumbler type lock. Furthermore, the instrument is simple in construction, inexpensive to manufacture and does not require a detection by feeling or sound to ascertain the correct shape to which a key blank must be cut.

Having described my invention, I claim:

1. A decoding instrument for a lock of the type having an elongated body, which body is bored longitudinally to receive a rotatable barrel in the bore, which barrel has a plurality of longitudinally disposed, radially extending bores and a slot, the bore of the body having a plurality of radially extending, longitudinally disposed bores that are aligned, respectively, with the radially extending bores in the barrel, each of the bores having a pin therein, and each of the radially extending bores in the body having a spring therein yieldingly urging the pins in those bores radially inwardly, said slot adapted to receive a key extending longitudinally through the slot in the barrel, said key having a plurality of teeth of different lengths that effect radial movements of the pins to radial positions allowing the key and barrel to rotate in the bore, said instrument comprising,

a frame having an elongated projecting key shaped support with an upper surface for supporting a plurality of decoders forming the upper portion of the key shape,

said decoders comprising a plurality of elongated support members,

said support members each having extending from the upper surface thereof, a tooth with inclined sides and being slidably mounted on said frame for longitudinal movement relative to the other support members and teeth,

said teeth being longitudinally positioned on said support members to be generally aligned with said radially extending longitudinally disposed bores,

the combined thickness of the support members being less than the width of the key-receiving slot in the barrel,

said frame having graduated indicia thereon corresponding to the longitudinal positions of the support members,

each of said support members being connected to a means mounted on said frame for independently reciprocating the associated support member to move a particular one of said teeth, whereby each of said teeth is independently moved longitudinally with respect to a corresponding one of said pins in said lock,

and each of said support members having indicia for mating with the indicia on the frame whereby when the pins are moved radially by said teeth to conditions of resistance to movement, the indicia on said frame and said support members indicates the key cut dimensions necessary to enable one to make a key which will open said lock.

2. A- decoding instrument as defined in claim 1, characterized by:

means for pivotally securing the plurality of reciprocating means on the frame.

3. A decoding instrument as defined in claim 1, characterized in that the elongated support for the decoders includes:

an elongated shoulder providing a guide for the decoders.

4. A decoding instrument as claimed in claim 1, characterized by:

each of said support members comprising a thin shim member.

5. A decoding instrument for a lock of the type having an elongated body, which body is bored longitudinally to receive a rotatable barrel in the bore, which barrel has a plurality of longituidnally disposed, radially extending bores and a slot, the bore of the body having a plurality of radially extending, longitudinally disposed bores that are aligned, respectively, with the radially extending bores in the barrel, each of the bores having a pin therein, and each of the radially extending bores in the body having a spring therein yieldingly urging the pins in those bores radially inwardly, said slot adapted to receive a key extending longitudinally through the slot in the barrel, said key having a plurality of teeth of different lengths, that effect radial movements of the pins to radial positions allowing the key and barrel to rotate in the bores, said instrument comprising:

a plurality of decoder teeth with inclined sides carried on a frame,

means mounted on said frame for selectively longitudinally moving and independntly positioning each of said decoder teeth under a given one of said pins simultaneously to raise each of said pins to the resistance to movement level,

and indicator means on said frame and said moving and positioning means for determining the longitudinal position of each of said teeth, whereby when said pins are at the resistance to movement level, a key shape capable of opening said lock can be produced. 

1. A decoding instrument for a lock of the type having an elongated body, which body is bored longitudinally to receive a rotatable barrel in the bore, which barrel has a plurality of longitudinally disposed, radially extending bores and a slot, the bore of the body having a plurality of radially extending, longitudinally disposed bores that are aligned, respectively, with the radially extending bores in the barrel, each of the bores having a pin therein, and each of the radially extending bores in the body having a spring therein yieldingly urging the pins in those bores radially inwardly, said slot adapted to receive a key extending longitudinally through the slot in the barrel, said key having a plurality of teeth of different lengths that effect radial movements of the pins to radial positions allowing the key and barrel to rotate in the bore, said instrument comprising, a frame having an elongated projecting key shaped support with an upper surface for supporting a plurality of decoders forming the upper portion of the key shape, said decoders comprising a plurality of elongated support members, said support members each having extending from the upper surface thereof, a tooth with inclined sides and being slidably mounted on said frame for longitudinal movement relative to the other support members and teeth, said teeth being longitudinally positioned on said support members to be generally aligned with said radially extending longitudinally disposed bores, the combined thickness of the support members being less than the width of the key-receiving slot in the barrel, said frame having graduated indicia thereon corresponding to the longitudinal positions of the support members, each of said support members being connected to a means mounted on said frame for independently reciprocating the associated support member to move a particular one of said teeth, whereby each of said teeth is independently moved longitudinally with respect to a corresponding one of said pins in said lock, and each of said support members having indicia for mating with the indicia on the frame whereby when the pins are moved radially by said teeth to conditions of resistance to movement, the indicia on said frame and said support members indicates the key cut dimensions necessary to enable one to make a key which will open said lock.
 2. A decoding instrument as defined in claim 1, characterized by: means for pivotally securing the plurality of reciprocating means on the frame.
 3. A decoding instrument as defined in claim 1, characterized in that the elongated support for the decoders includes: an elongated shoulder providing a guide for the decoders.
 4. A decoding instrument as claimed in claim 1, characterized by: each of said support members comprising a thin shim member.
 5. A decoding instrument for a lock of the type having an elongated body, which body is bored longitudinally to receive a rotatable barrel in the bore, which barrel has a plurality of longituidnally disposed, radially extending bores and a slot, the bore of the body having a plurality of radially extending, longitudinally disposed bores that are aligned, respectively, with the radially extending bores in the barrel, each of the bores having a pin therein, and each of the radially extending bores in the body having a spring therein yieldingly urging the pins in those bores radially inwardly, said slot adapted to receive a key extending longitudinally through the slot in the barrel, said key having a plurality of teeth of different lengths, that effect radial movements of the pins to radial positions allowing the key and barrel to rotate in the bores, said instrument comprising: a plurality of decoder teeth with inclined sides carriEd on a frame, means mounted on said frame for selectively longitudinally moving and independntly positioning each of said decoder teeth under a given one of said pins simultaneously to raise each of said pins to the resistance to movement level, and indicator means on said frame and said moving and positioning means for determining the longitudinal position of each of said teeth, whereby when said pins are at the resistance to movement level, a key shape capable of opening said lock can be produced. 